Wu Ren-Xiang, Zheng Gao-Feng, Li Wen-Wang, Zhong Lu-Bin, Zheng Yu-Ming
CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, 361021 Xiamen, China.
Department of Instrumental and Electrical Engineering, Xiamen University, 361005 Xiamen, China.
J Nanosci Nanotechnol. 2018 Aug 1;18(8):5624-5635. doi: 10.1166/jnn.2018.15433.
The preparation, characterization and application of chitosan (CS) based electrospun nanofiber membrane for the adsorptive removal of Cu(II) from water were systematically investigated. Homogeneous, porous polyvinyl alcohol (PVA)/CS nanofiber membrane with amorphous structure, and average fiber diameter of 49 nm was successfully fabricated. The adsorption of Cu(II) onto the positively charged PVA/CS nanofiber membrane (pH < 6) was due to chemisorption rather than electrostatic adherence, and was highly pH-dependent. The adsorption equilibrium of Cu(II) by the PVA/CS nanofiber was established within 120 min, which was much faster than that by CS beads, and the adsorption kinetics followed pseudo-second-order model well (r 2 > 0.995). The adsorption isotherm data were well fitted with Langmuir model, and the maximum Cu(II) adsorption capacity of PVA/CS nanofiber membrane was 90.3 mg·g-1, which was much higher than that of CS beads. The adsorbed Cu(II) formed strong inner-sphere complex with the adsorbent. Coexisting cations of iron, lead, cadmium, nickel, calcium, and magnesium have insignificant effect on the Cu(II) adsorption, indicating the adsorbent has good selectivity for Cu(II) adsorption. FTIR and XPS analysis reveal amine, hydroxyl and ether groups are responsible for the Cu(II) adsorption. This work demonstrates the electrospun PVA/CS nanofiber membrane is a promising adsorbent for heavy metal removals.
系统研究了基于壳聚糖（CS）的电纺纳米纤维膜用于从水中吸附去除Cu（II）的制备、表征及应用。成功制备了具有非晶结构、平均纤维直径为49 nm的均匀、多孔聚乙烯醇（PVA）/CS纳米纤维膜。带正电荷的PVA/CS纳米纤维膜（pH < 6）对Cu（II）的吸附是由于化学吸附而非静电吸附，且高度依赖于pH值。PVA/CS纳米纤维对Cu（II）的吸附平衡在120分钟内达到，比CS珠的吸附平衡快得多，吸附动力学很好地遵循准二级模型（r 2 > 0.995）。吸附等温线数据与Langmuir模型拟合良好，PVA/CS纳米纤维膜对Cu（II）的最大吸附容量为90.3 mg·g-1，远高于CS珠。吸附的Cu（II）与吸附剂形成强内球络合物。铁、铅、镉、镍、钙和镁等共存阳离子对Cu（II）吸附影响不显著，表明该吸附剂对Cu（II）吸附具有良好的选择性。傅里叶变换红外光谱（FTIR）和X射线光电子能谱（XPS）分析表明，胺基、羟基和醚基是Cu（II）吸附的原因。这项工作表明，电纺PVA/CS纳米纤维膜是一种有前景的重金属去除吸附剂。
